passing thru root reference

.gitignore

@@ -8,3 +8,6 @@ wheels/
 
 # Virtual environments
 .venv
+
+
+*.ipynb

Dev.ipynb

@@ -1,19 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "e1b794f1",
-   "metadata": {},
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "language_info": {
-   "name": "python"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 5
-}

src/hooked_containers/__init__.py

@@ -1,2 +0,0 @@
-def hello() -> str:
-    return "Hello from hooked-containers!"

src/hooked_containers/container.py

@@ -1,52 +1,59 @@
 from abc import ABC, abstractmethod
 from collections.abc import Container, Iterable, MutableMapping, MutableSequence, Sized
-from typing import Protocol, TypeVar
+from typing import TypeVar
 
 from . import events as e
+from .events import HookFunction
+from .types import MutableNesting
 
 T = TypeVar("T")
 
-type MutableNesting[T] = T | MutableSequence[T] | MutableMapping[T, MutableNesting[T]]
-
-
-class HookFunction(Protocol):
-    def __call__(self, event: e.ChangeEvent[T]) -> None: ...
-
 
 class HookedContainer(ABC, Sized, Iterable[T], Container[T]):
+    _data: MutableNesting[T]
     _path: MutableSequence[int]
+    _root: MutableMapping[T] | MutableSequence[T] | None = None
     hook: HookFunction
 
     def __repr__(self):
         return f"{self.__class__.__name__}({self._data!r})"
 
+    def __len__(self):
+        return len(self._data)
+
+    def __iter__(self):
+        return iter(self._data)
+
+    def __contains__(self, x):
+        return x in self._data
+
     # Sequence Methods
     # __contains__, __iter__, __reversed__, index, and count
 
     @abstractmethod
     def __getitem__(self, key): ...
 
-    def __len__(self):
-        return len(self._data)
-
     # MutableSequence Methods
     # append, reverse, extend, pop, remove, and __iadd__
 
     def __setitem__(self, s, value):
         self._data[s] = value
         if self.hook:
-            self.hook(e.SetItemEvent(index=s, item=value, path=self._path))
+            self.hook(e.SetItemEvent(self._root, self.new_path(s), value))
 
     def __delitem__(self, s):
         item = self._data.pop(s)
         if self.hook:
-            self.hook(e.RemoveItemEvent(index=s, item=item, path=self._path))
+            self.hook(e.RemoveItemEvent(self._root, self.new_path(s), item))
 
-    @abstractmethod
+    # @abstractmethod
-    def insert(self, index, value): ...
+    # def insert(self, index, value): ...
 
     # Custom Methods
 
+    def new_path(self, key):
+        return (*self._path, key)
+
     def get_nested(self, keys):
         """Recursively call __getitem__ with each key in the iterable."""
         result = self

src/hooked_containers/events.py

@@ -1,27 +1,33 @@
+from __future__ import annotations
+
 from collections.abc import MutableSequence
-from dataclasses import dataclass
+from dataclasses import dataclass, field
-from typing import Generic, TypeVar
+from typing import TYPE_CHECKING, Generic, Protocol, TypeVar
+
+if TYPE_CHECKING:
+    from .mapping import HookedMapping
 
 T = TypeVar("T")
 
 
 @dataclass(frozen=True)
 class ChangeEvent(Generic[T]):
-    index: int
+    root: HookedMapping[T] = field(repr=False)
-    item: T
+    path: MutableSequence[int]
-    path: MutableSequence[int] | None = None
-
-
-@dataclass(frozen=True)
-class AddItemEvent(ChangeEvent[T]):
     item: T
 
 
 @dataclass(frozen=True)
-class SetItemEvent(ChangeEvent[T]):
+class AddItemEvent(ChangeEvent[T]): ...
-    item: T
 
 
 @dataclass(frozen=True)
-class RemoveItemEvent(ChangeEvent[T]):
+class SetItemEvent(ChangeEvent[T]): ...
-    item: T
+
+
+@dataclass(frozen=True)
+class RemoveItemEvent(ChangeEvent[T]): ...
+
+
+class HookFunction(Protocol):
+    def __call__(self, event: ChangeEvent[T]) -> None: ...

src/hooked_containers/mapping.py

@@ -1,9 +1,9 @@
-from collections.abc import MutableMapping, Sequence
+from collections.abc import MutableMapping, MutableSequence
-from copy import copy
 from typing import TypeVar
 
 from . import events as e
-from .common import HookedContainer, MutableNesting
+from .container import HookedContainer, MutableNesting
+from .events import HookFunction
 
 T = TypeVar("T")
 
@@ -13,33 +13,60 @@ class HookedMapping(HookedContainer[T], MutableMapping[T, MutableNesting[T]]):
 
     def __init__(
         self,
-        hook,
         existing: MutableMapping[T, MutableNesting[T]],
-        path: Sequence[int] | None = None,
+        hook: HookFunction | None = None,
+        root: MutableMapping[T] | None = None,
+        path: MutableSequence[int] | None = None,
     ):
-        self.hook = hook
+        match existing:
+            case HookedMapping(_data=seq):
+                self._data = seq
+            case MutableMapping() as seq:
+                self._data = seq
+            case _:
+                raise TypeError(f"Expected a mapping, got {type(existing)}")
+                # self._data = dict(it)
         self._data = existing
+        self.hook = hook
+        self._root = root if root is not None else self
         self._path = list(path) if path is not None else []
 
+    def __wrap_sub__(self, other, **kwargs):
+        return HookedMapping(other, hook=self.hook, root=self._root, **kwargs)
+
     def __getitem__(self, key: T) -> MutableNesting[T]:
+        if key not in self._data:
+            return self.__wrap_sub__(self.__setitem__(key, {}), path=self.new_path(key))
         value = self._data[key]
-        new_path = copy(self._path)
-        new_path.append(key)
         match value:
             case MutableMapping() as mapping:
-                return HookedMapping(mapping, self.hook, path=new_path)
+                return self.__wrap_sub__(mapping, path=self.new_path(key))
-            case HookedContainer() as seq:
-                return type(self)(seq, self.hook, path=new_path)
             case _ as item:
                 return item
 
-    def __setitem__(self, key: T, value: MutableNesting[T]) -> None:
+    def __setitem__(
+        self,
+        key: T,
+        value: MutableNesting[T],
+        *,
+        suppress_hook: bool = False,
+    ) -> MutableNesting[T] | None:
+        new_path = self.new_path(key)
+        event = (
+            e.SetItemEvent(self._root, new_path, value)
+            if key in self._data
+            else e.AddItemEvent(self._root, new_path, value)
+        )
+        match value:
+            case HookedMapping(_data=value):
                 self._data[key] = value
-        if self.hook:
+            case _:
-            self.hook(e.SetItemEvent(index=key, item=value))
+                self._data[key] = value
+        if self.hook and not suppress_hook:
+            self.hook(event)
+        return value
 
     def __delitem__(self, key: T) -> None:
-        item = self._data[key]
+        item = self._data.pop(key)
-        del self._data[key]
         if self.hook:
-            self.hook(e.RemoveItemEvent(index=key, item=item, path=self._path))
+            self.hook(e.RemoveItemEvent(self._root, self.new_path(key), item))

src/hooked_containers/sequence.py

@@ -3,7 +3,9 @@ from copy import copy
 from typing import TypeVar
 
 from . import events as e
-from .common import HookedContainer, HookFunction
+from .container import HookedContainer
+from .events import HookFunction
+from .types import MutableNesting
 
 T = TypeVar("T")
 
@@ -16,6 +18,7 @@ class HookedList(HookedContainer[T], MutableSequence[T]):
         self,
         existing: MutableSequence[T],
         hook: HookFunction | None = None,
+        root: MutableNesting[T] | None = None,
         path: MutableSequence[int] | None = None,
     ) -> None:
         self.hook = hook
@@ -26,6 +29,7 @@ class HookedList(HookedContainer[T], MutableSequence[T]):
                 self._data = seq
             case _ as it:
                 self._data = list(it)
+        self._root = root if root is not None else self
         self._path = list(path) if path is not None else []
 
     def __getitem__(self, s):
@@ -33,13 +37,13 @@ class HookedList(HookedContainer[T], MutableSequence[T]):
         new_path.append(s)
         match self._data[s]:
             case HookedContainer(_data=seq):
-                return type(self)(seq, self.hook, path=new_path)
+                return type(self)(seq, self.hook, root=self._root, path=new_path)
             case MutableSequence() as seq:
-                return HookedList(seq, self.hook, path=new_path)
+                return HookedList(seq, self.hook, root=self._root, path=new_path)
             case _ as item:
                 return item
 
     def insert(self, index, value):
         self._data.insert(index, value)
         if self.hook:
-            self.hook(e.AddItemEvent(index=index, item=value, path=self._path))
+            self.hook(e.AddItemEvent(self._root, self.new_path(index), value))

src/hooked_containers/state.py

@@ -1,22 +1,43 @@
+from collections.abc import MutableMapping
 from datetime import datetime
 
 from .mapping import HookedMapping
 
 
-class DomainState(HookedMapping[str]):
+class EntityState(HookedMapping[str]):
     def __setitem__(self, key, value):
         super().__setitem__(key, value)
-        super().__setitem__("last_changed", datetime.now())
+        super().__setitem__("last_changed", datetime.now(), suppress_hook=True)
+
+
+class DomainState(HookedMapping[str]):
+    _data: MutableMapping[str, EntityState]
+
+    def __getitem__(self, key):
+        match super().__getitem__(key):
+            case HookedMapping(_data=val):
+                return EntityState(val, hook=self.hook, path=self.new_path(key))
+            case _ as val:
+                raise TypeError(f"Expected a mapping for domain state, got {type(val)}")
 
 
 class NameSpaceState(HookedMapping[str]):
-    _data: DomainState
+    _data: MutableMapping[str, DomainState]
-
-    def __setitem__(self, key, value):
-        super().__setitem__(key, value)
-        # print("ns SetItem")
 
     def __getitem__(self, key):
-        val = super().__getitem__(key)
+        match super().__getitem__(key):
-        # print("ns GetItem")
+            case HookedMapping(_data=val):
-        return DomainState(self.hook, existing=val, path=self._path + [key])
+                return DomainState(val, hook=self.hook, path=self.new_path(key))
+            case _ as val:
+                raise TypeError(f"Expected a mapping for domain state, got {type(val)}")
+
+
+class FullState(HookedMapping[str]):
+    _data: MutableMapping[str, NameSpaceState]
+
+    def __getitem__(self, key):
+        match super().__getitem__(key):
+            case HookedMapping(_data=val):
+                return NameSpaceState(val, hook=self.hook, path=self.new_path(key))
+            case _ as val:
+                raise TypeError(f"Expected a mapping for namespace state, got {type(val)}")

src/hooked_containers/types.py

@@ -0,0 +1,6 @@
+from collections.abc import MutableMapping, MutableSequence
+from typing import TypeVar
+
+T = TypeVar("T")
+
+type MutableNesting[T] = T | MutableSequence[T] | MutableMapping[T, MutableNesting[T]]

tests/test_mapping.py

@@ -0,0 +1,68 @@
+from dataclasses import dataclass, field
+
+from hooked_containers import events as e
+from hooked_containers.mapping import HookedMapping
+
+
+@dataclass
+class HookTracker:
+    added: list[e.AddItemEvent] = field(default_factory=list)
+    set: list[e.SetItemEvent] = field(default_factory=list)
+    removed: list[e.RemoveItemEvent] = field(default_factory=list)
+
+    def hook(self, event: e.ChangeEvent):
+        match event:
+            case e.AddItemEvent():
+                self.added.append(event.item)
+            case e.SetItemEvent():
+                self.set.append(event.item)
+            case e.RemoveItemEvent():
+                self.removed.append(event.item)
+
+
+class TestHookedMapping:
+    class TestConstruction:
+        def test_empty(self):
+            m = HookedMapping({})
+            assert m._data == {}
+            assert dict(m) == {}
+
+        def test_with_existing(self):
+            existing = {"a": 1, "b": 2}
+            og_id = id(existing)
+            m = HookedMapping(existing)
+            assert id(m._data) == og_id
+            assert dict(m) == existing
+
+        def test_nesting(self):
+            existing = {"a": {"x": 1}, "b": {"y": 2}}
+            m = HookedMapping(existing)
+            assert dict(m) == existing
+            assert dict(m["a"]) == {"x": 1}
+            assert dict(m["b"]) == {"y": 2}
+
+    class TestMappingOps:
+        def test_setitem(self):
+            tracker = HookTracker()
+            m = HookedMapping({}, tracker.hook)
+            m["a"] = 1
+            assert m._data == {"a": 1}
+            assert tracker.added == [1]
+
+        def test_nested_setitem(self):
+            tracker = HookTracker()
+            m = HookedMapping({"a": {}}, tracker.hook)
+            m["a"]["x"] = 1
+            assert m._data == {"a": {"x": 1}}
+            assert tracker.added == [1]
+
+        def test_getitem(self):
+            m = HookedMapping({"a": 1})
+            assert m["a"] == 1
+
+        def test_delitem(self):
+            tracker = HookTracker()
+            m = HookedMapping({"a": 1}, tracker.hook)
+            del m["a"]
+            assert not m["a"]
+            assert tracker.removed == [1]